Poly(N-vinyl-2-pyrrolidone), also known as polyvinylpyrrolidone, PVP, Povidone, or Plasdone, is a water-soluble polymer used commercially in such products as aerosol hair sprays, adhesives, lithographic solutions, pigment dispersions, and drug, detergent, and cosmetic formulations. PVP has been used extensively in medicine since 1939. The earliest use of PVP in medicine was during World War II when a 3.5% solution of PVP was infused into patients as a synthetic blood plasma volume expander. The toxicity of PVP, extensively studied in a variety of species including humans and other primates, is extremely low. PVP has also found use as internal wetting agents in contact lens applications.
PVP film surfaces have been reduced with sodium borohydride to form hydroxyl groups on film surfaces. However, hydroxyl groups were not formed on the bulk polymer.
Poly-N-vinylpyrrolid-2-one has been modified to contain two identical reactive groups in the molecule via the free radical polymerization of N-vinylpyrrolid-2-one in the presence of hydrogen peroxide as the free radical initiator followed by treatment with a complex hydride (such as sodium boranate and lithium boranate). The highly reactive complex hydrides were employed in amounts that were low (0.5 to 5 weight percent), so the lactam group of the polyvinylpyrrolidone was not attacked. The resultant polymer was chain extended with a reactive bifunctional compound, yielding a polymer that had a molecular weight at least 2.5 times higher than that of the starting polymer.
Polyvinylpyrrolidone (PVP) has long been used in biomedical applications. PVP derivatives, such as hydroxyl-functionalized polyvinylpyrrolidone, have reactive moieties along the polymer backbone that can be reacted to form new polymers with desirable properties. There remains a need for hydroxyl-functionalized polyvinylpyrrolidones having hydroxyl moieties distributed randomly throughout the polyvinylpyrrolidone backbone.